12.
JUPIter’s magnetic field<br />Just like on Earth, Jupiter’s magnetosphere produces aurora concentrated in the rings around the magnetic poles.<br />1000 times more powerful than the aurora on Earth.<br />

15.
Jupiter’s cloud belts<br /><ul><li>On Jupiter, the poles and equator have about the same temperature; no wave-shaped winds but rather bands called belts and zones.</li></ul>On Earth, the temperature difference b/w poles and equator drives a wave-shaped wind organizing high and low pressure areas.<br />

17.
The Great red spot<br />Several bright and dark spots mixed in with cloud structure.<br />Cyclones/Anticyclones<br />Largest and most prominent: Great Red Spot.<br />Visible for over 300 years.<br />Formed by rising gas carrying heat from below the clouds, creating a vast, rotating storm.<br /><ul><li>For the first time, very recently, a new similar red storm system has been observed, Red Jr.</li></li></ul><li>Jupiter’s rings<br />Discovered in 1979 by Voyager 1.<br />Dark and reddish in color; rocky rather than icy (mostly microscopic particles).<br />Orbit inside the Roche Limit, the distance from a planet within which a moon cannot hold itself together by its own gravity.<br />International Space Station can orbit inside Earth’s Roche Limit; held together by bolts and welds.<br />Can’t be old  pressure of sunlight and Jupiter’s extensive magnetic field cause ring particles to spiral into cloud layers of Jupiter.<br />Frequently replenished.<br />Fainter rings known as gossamer rings, extend twice as far from Jupiter than the main ring.<br />

23.
Albedo of 0.69, meaning it reflects 69% of the light hitting its surface.</li></li></ul><li>Surface of europa<br />Long cracks in the icy crust and sections moving apart as if they were icebergs floating on water provide further evidence for tectonic activity.<br />

29.
Inward Focusing of Meteorites</li></li></ul><li>Callisto: the ancient face <br />Average density ~ 1.8 g/cm3<br />Mixture of ice and rocks.<br />Old, dark surface heavily cratered.<br />Measurements show it never fully differentiated to form a dense core and lower-density mantle.<br />Interaction with Jupiter’s magnetic field suggests is has a layer of liquid water.<br />Heat from interior through slow radioactive decay.<br /><ul><li>Impact scar shown above is one of the largest in the solar system (4000 km ~ 2500 mi).</li></li></ul><li>the galilean moons<br />Minor moons are believed to be captured asteroids.<br />Galilean moons probably formed with Jupiter.<br />Formed from a disk of material surrounding Jupiter (mini “solar nebula”).<br />Earliest moons may have spiraled into Jupiter.<br />Galilean moons are probably a 2nd generation of moons for Jupiter.<br />

31.
Saturn’s atmosphere<br />Hydrogen and Helium rich with heavy element core.<br />Displays belt-zone circulation, similar patterns to Jupiter (not as distinct).<br />Actually exhibits faster wind speeds, but fewer wind zones.<br /><ul><li>Much colder atmosphere than Jupiter’s (twice as far from the Sun, receives only ¼ as much solar energy per square meter).</li></li></ul><li>Saturn’s rings<br />An astronomer once said: <br />“ The rings are made of beautiful physics.”<br />In 1609, Galileo became the first to see the rings, but didn’t recognize them as individual rings.<br />Drew Saturn as a central body with two smaller bodies surrounding it.<br />

33.
Saturn’s rings<br />Made of billions of ice particles (microscopic specks  chunks larger than a house).<br />Voyager 1<br />Voyager 2<br />Cassini<br />Rings could not have formed when Saturn formed  once hot and ring material would have vaporized.<br />

38.
History of saturn<br />SATURN<br />“God of Harvest”<br />Most of Saturn’s story parallels Jupiter’s.<br />Smaller with less liquid metallic Hydrogen, thus producing a weaker magnetic field.<br />Rings are not primordial, meaning the material in them now has not been in its current form since the formation of the planet.<br />Permanent or temporary?<br />

39.
uranus<br />Chance discovery made by William Herschel in 1781 while scanning the sky for nearby objects with measurable parallax.<br />Until that time, astronomers only knew of five planets aside from Earth.<br />“Luck is what happens to the people who work hard.”<br />

45.
Uranus’ magnetic field<br />Lower mass than Jupiter; internal pressure not high enough to create liquid metallic Hydrogen.<br />No magnetic field was expected.<br />Voyager 2 detected slight magnetic field (75% of Earth’s).<br />Theorists say it is generated by a dynamo effect not from the interior like on Earth and other planets, but from surface layers of liquid water with dissolved ammonia and methane (convection currents)  good conductor of electricity, rotation coupled together = magnetic field.<br />

47.
Rings of uranus<br />Similar to Jupiter’s rather than Saturn’s.<br />Dark/faint, not easily visible, and contained by shepherd satellites.<br />Like all Jovian rings, they cannot survive for long periods; need to be replenished with material from impacts on moons.<br />

50.
Moons of uranus<br />Miranda is the innermost and most unique of the moons of Uranus.<br /><ul><li>Originally believed to be broken apart and accreted back together.

51.
Consists of ovoids, or oval-grooved patterns most likely associated with convection currents in the mantle, not with impacts.

52.
Old surface features suggest Miranda is no longer active.</li></li></ul><li>HISTORY OF URANUS<br />URANUS<br />“God of the Sky”<br />Difficult to study and observe.<br />Far away/peculiar in many ways.<br />Computer models suggest it probably formed closer to the Sun, along with Neptune, in the field of Jupiter and Saturn.<br />Gravitational interactions may have eventually moved them outward to their present locations.<br />Interesting hypotheses exist.<br />

54.
Neptune’s atmosphere<br />Belt-zone structured clouds with high speed winds; similar to other Jovians.<br />Great Dark Spotsimilar cyclonic disturbance to Jupiter’s Great Red Spot.<br />White cloud features on the planet are methane-ice crystals.<br />

55.
Neptune’s rings<br />Voyager 2 revealed rings of Neptune, as expected.<br />Can’t be primordial they couldn’t have lasted in their present form since the formation of Neptune.<br />

56.
Moons of neptune<br />2 largest moons of Neptune visible from Earth-based telescopes; Tritonand Nereid.<br />6 more discovered by Voyager 2.<br />The orbit of Nereid is highly eccentric compared to the orbit of Triton.<br />

60.
Surface of pluto<br />Little surface detail is shown, even from the Hubble Space Telescope.<br />If all goes well, the New Horizons probe, due to arrive in 2015, will send the first close-up images of Pluto and its moons.<br />Cold enough to freeze most compounds you think of as gases.<br />Maximum daytime temperature ~ 55K (-360 F); enough to vaporize some of the Nitrogen and Carbon Monoxide and some Methane to form a thin atmosphere around Pluto.<br />Atmosphere first detected in 1988.<br />

61.
Pluto’s moons<br />Largest moon, Charon, was discovered in 1978.<br />Half the diameter of Pluto.<br />Believed to contain 35% ice and 65% rock material.<br />Two smaller moons, Nix and Hydra, were found in 2005 and confirmed in 2006 by the Hubble Space Telescope.<br />

62.
Origin of pluto<br />Believed to have a very different history than its neighboring four Jovian planets.<br />Pluto and its moons are now considered members of the Kuiper Belt, icy objects beyond Neptune’s orbit (similar to Asteroid Belt between Mars and Jupiter only much larger).<br /><ul><li>Because of its different origin from the planets, Pluto is now classified as a dwarf planet.</li></li></ul><li>Objects Beyond Neptune<br />In recent years, astronomers have discovered hundreds of objects beyond Neptune’s orbit and have termed them Trans-Neptunian Objects (TNO’s).<br />Most are just small chunks of ice.<br />TNO’s exist in a region known as the Kuiper Belt.<br />

63.
Family of Dwarf planets<br />In order to be considered a dwarf planet, the object must meet the following criteria:<br />Orbits the Sun<br />Is round because of its own gravity (mass-related)<br />Has not cleared the region around its orbit<br />Is not a satellite of another planet<br />CERES<br />The largest asteroid<br />Member of the Asteroid Belt<br />900 km diameter<br />ERIS<br />The “10th” planet<br />4% larger than Pluto<br />27% more massive than Pluto<br />70% further away from the Sun than Pluto<br />